usr/src/common/util/memchr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 /*      Copyright (c) 1988 AT&T */
  30 /*        All Rights Reserved   */
  31
  32
  33 #include <sys/types.h>
  34 #if defined(_KERNEL)
  35 #include <sys/systm.h>
  36 #else
  37 #include <string.h>
  38 #include <stddef.h>
  39 #endif
  40
  41 /*
  42  * Return the ptr in sptr at which the character c1 appears;
  43  * or NULL if not found in n chars; don't stop at \0.
  44  */
  45 void *
  46 memchr(const void *sptr, int c1, size_t n)
  47 {
  48         if (n != 0) {
  49                 unsigned char c = (unsigned char)c1;
  50                 const unsigned char *sp = sptr;
  51
  52                 do {
  53                         if (*sp++ == c)
  54                                 return ((void *)--sp);
  55                 } while (--n != 0);
  56         }
  57         return (NULL);
  58 }